In recent years Derrida has devoted a considerable number of writings to addressing "the question of the animal," and, more often than not, this question arises in a reading of one of Heidegger's texts. In order to appreciate more fully the stakes of Derrida's posing of this question in relation to Heidegger, in this essay I offer some prefatory remarks to the question of the animal in Derrida's reading of Heidegger. The essay opens with a careful analysis of Derrida's early essay "The Ends of Man," in which Heidegger's "Letter on "Humanism"' is read in terms of the motif of man's "proper." Taking my point of departure from this Derridean reading of Heidegger's humanism, I return to Heidegger's "Letter" in order to uncover the manner in which Heidegger distinguishes man's "proper" from what is "improper," namely, animality. This reading reveals that, while Heidegger offers a convincing account of the limits of metaphysical humanism, this critical account nevertheless ends up uncritically reinforcing the anthropocentrism of this same tradition. My closing suggestion is that Derrida's rethinking of animality should be understood as an extended meditation on the various consequences and effects of this dogmatic anthropocentrism in Heideggerian and post-Heideggerian thought.